(a) Field of the Invention
The present invention relates to a method of forming an electrode pattern in an electrode layer which is used in liquid crystal optical devices, touch panels, EL elements, or the like.
(b) Description of the Related Art
In the conventional method of forming an electrode pattern, there has generally been employed photolithography technique where an electrode pattern is formed by carrying out sequential steps including coating a conductive film covering a substrate with a photoresist, placing a circuit pattern film thereon, printing the pattern onto the photoresist by exposure, etching the conductive film in the areas other than the areas under the developed pattern of the photoresist, and removing the developed pattern of the photoresist. However, this method includes many steps, and development and etching are liable to go amiss when a fine pattern is formed in a conductive film of a large area, thereby decreasing the yield.
As a means of dissolving the problem, in Japanese Patent Application Kokai Koho (Laid-open) No. 63-18330, there is proposed a method where a laser beam is applied to a conductive film in vacuum to remove the conductive film in the areas where the laser beam is applied. This method, however, also involves some problems. For example, scalping up of equipments is inevitable because of the necessity for applying a laser beam in vacuum, and high power sources of laser beam and the optical system for moving the areas applied with the laser beam are very expensive. Furthermore, when plastic substrates are used, destruction is not limited in conductive films on the plastic substrates but extends into the plastics substrates.